Comparison of a laboratory-developed RT-PCR and the CDC RT-PCR protocol with rapid immunodiagnostic testing during the 2009 H1N1 influenza A pandemic

We evaluated the performance of a laboratory-developed multiplex real-time reverse transcription-PCR assay (LDT rRT-PCR), the Centers for Disease Control and Prevention (CDC) 2009 H1N1 rRT-PCR protocol using the LightCycler 480 II, the multiplex xTAG Respiratory Virus Panel (xTAG RVP), and rapid immunodiagnostic testing (RIDT) using the BinaxNOW Influenza A & B to detect 2009 H1N1 with 426 nasopharyngeal swab specimens during the 2009 H1N1 pandemic. The specificity of the methods tested was ≥98%, and the individual test sensitivities were RIDT at 42.3% [95% confidence interval (CI), 31.4–54.0], LDT rRT-PCR at 98.9% (95% CI, 92.9–99.9), CDC 2009 H1N1 rRT-PCR at 78.2% (95% CI, 67.8–86.0), and xTAG RVP at 93.1% (95% CI, 85.0–97.2). A negative RIDT result should not be used to make decisions with respect to treatment or infection prevention. rRT-PCR is the preferred first-line diagnostic test for detecting 2009 H1N1 influenza A.